The present invention relates to a data transfer control device, electronic equipment, and a data transfer control method.
The market for Universal Serial Bus (USB) 2.0 which supports the High Speed (HS) mode has grown steadily. An interface standard called USB On-The-Go (OTG) has been standardized by the USB Implementers Forum (USB-IF). The OTG standard (OTG 1.0) which is an extension of USB 2.0 has the potential for creating new added value for the USB interface, and development of applications making use of its characteristics has been anticipated.
According to OTG, peripherals (peripheral devices) which have been connected with a host (personal computer or the like) through the USB can be allowed to have a function of a host. This enables peripherals to be connected through the USB and data to be transferred therebetween. For example, if a digital camera is directly connected with a printer, an image from the digital camera can be printed by the printer. If a digital camera or a digital video camera is connected with a storage device, data in the digital camera or digital video camera can be stored in the storage device.
However, a low performance CPU (processing unit) is generally incorporated in the peripheral which is allowed to perform the host function by OTG. Therefore, if the processing load of the CPU (firmware) included in the peripheral is increased or processing is complicated by the addition of the host function, another processing may be hindered or the design period of the equipment may be increased.
Moreover, if the scale of a data transfer control device is increased by allowing the data transfer control device to perform the host function by OTG, costs of the data transfer control device and equipment (electronic equipment) in which the data transfer control device is incorporated are increased.